On Tue, May 01, 2018 at 06:24:07PM +0800, Xin Long wrote:
> This patch is to implement sctp_sendv and sctp_recvv defined in
> rfc6458#section-9.12 and 9.13. They provide an extensible way
> for users to send or receive messages from a SCTP socket.
>
> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
> ---
> src/include/netinet/sctp.h | 43 ++++++++++++
> src/lib/Versions.map | 2 +
> src/lib/recvmsg.c | 88 +++++++++++++++++++++++++
> src/lib/sendmsg.c | 161 +++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 294 insertions(+)
>
> diff --git a/src/include/netinet/sctp.h b/src/include/netinet/sctp.h
> index a0cd14c..701f091 100644
> --- a/src/include/netinet/sctp.h
> +++ b/src/include/netinet/sctp.h
> @@ -122,6 +122,49 @@ int sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
> /* Return the address length for an address family. */
> int sctp_getaddrlen(sa_family_t family);
>
> +
> +/* sendv infotype */
> +enum {
> + SCTP_SENDV_NOINFO,
> + SCTP_SENDV_SNDINFO,
> + SCTP_SENDV_PRINFO,
> + SCTP_SENDV_AUTHINFO,
> + SCTP_SENDV_SPA
> +};
> +
> +/* sendv_flags */
> +#define SCTP_SEND_SNDINFO_VALID 0x1
> +#define SCTP_SEND_PRINFO_VALID 0x2
> +#define SCTP_SEND_AUTHINFO_VALID 0x4
> +
> +struct sctp_sendv_spa {
> + uint32_t sendv_flags;
> + struct sctp_sndinfo sendv_sndinfo;
> + struct sctp_prinfo sendv_prinfo;
> + struct sctp_authinfo sendv_authinfo;
> +};
> +
> +int sctp_sendv(int s, const struct iovec *iov, int iovcnt,
> + struct sockaddr *addrs, int addrcnt, void *info,
> + socklen_t infolen, unsigned int infotype, int flags);
> +
> +/* recvv infotype */
> +enum {
> + SCTP_RECVV_NOINFO,
> + SCTP_RECVV_RCVINFO,
> + SCTP_RECVV_NXTINFO,
> + SCTP_RECVV_RN
> +};
> +
> +struct sctp_recvv_rn {
> + struct sctp_rcvinfo recvv_rcvinfo;
> + struct sctp_nxtinfo recvv_nxtinfo;
> +};
> +
> +int sctp_recvv(int s, const struct iovec *iov, int iovlen,
> + struct sockaddr *from, socklen_t *fromlen, void *info,
> + socklen_t *infolen, unsigned int *infotype, int *flags);
> +
> #ifdef __cplusplus
> }
> #endif
> diff --git a/src/lib/Versions.map b/src/lib/Versions.map
> index a3c5561..7faad5d 100644
> --- a/src/lib/Versions.map
> +++ b/src/lib/Versions.map
> @@ -10,7 +10,9 @@ VERS_1 {
> sctp_opt_info;
> sctp_peeloff;
> sctp_recvmsg;
> + sctp_recvv;
> sctp_sendmsg;
> + sctp_sendv;
> sctp_send;
>
> local:
> diff --git a/src/lib/recvmsg.c b/src/lib/recvmsg.c
> index 4575788..7c1dcad 100644
> --- a/src/lib/recvmsg.c
> +++ b/src/lib/recvmsg.c
> @@ -99,3 +99,91 @@ int sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
>
> return (error);
> }
> +
> +int sctp_recvv(int s, const struct iovec *iov, int iovlen,
> + struct sockaddr *from, socklen_t *fromlen, void *info,
> + socklen_t *infolen, unsigned int *infotype, int *flags)
> +{
> + char incmsg[CMSG_SPACE(sizeof(struct sctp_rcvinfo) +
> + sizeof(struct sctp_nxtinfo))];
> + int error, len, _infolen;
> + struct cmsghdr *cmsg;
> + struct msghdr inmsg;
> +
> + memset(&inmsg, 0, sizeof(inmsg));
> +
> + /* set from and iov */
> + inmsg.msg_name = from;
> + inmsg.msg_namelen = fromlen ? *fromlen : 0;
> + inmsg.msg_iov = (struct iovec *)iov;
> + inmsg.msg_iovlen = iovlen;
> + inmsg.msg_control = incmsg;
> + inmsg.msg_controllen = sizeof(incmsg);
> +
> + error = recvmsg(s, &inmsg, flags ? *flags : 0);
> + if (error < 0)
> + return error;
> +
> + /* set fromlen, frags */
> + if (fromlen)
> + *fromlen = inmsg.msg_namelen;
> +
> + if (flags)
> + *flags = inmsg.msg_flags;
> +
> + if (!info || !infotype || !infolen)
> + return error;
> +
> + *infotype = SCTP_RECVV_NOINFO;
> + _infolen = *infolen;
> +
> + /* set info and infotype */
> + for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg != NULL;
> + cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
> + if (cmsg->cmsg_level != IPPROTO_SCTP)
> + continue;
> +
> + if (cmsg->cmsg_type == SCTP_RCVINFO) {
> + len = sizeof(struct sctp_rcvinfo);
> + if (*infotype == SCTP_RECVV_NOINFO) {
> + if (_infolen < len)
> + break;
> + memcpy(info, CMSG_DATA(cmsg), len);
> + *infotype = SCTP_RECVV_RCVINFO;
> + *infolen = len;
> + } else if (*infotype == SCTP_RECVV_NXTINFO) {
> + if (_infolen < len +
> + sizeof(struct sctp_nxtinfo))
> + break;
> + memcpy(info + len, info,
> + sizeof(struct sctp_nxtinfo));
> + memcpy(info, CMSG_DATA(cmsg), len);
> + *infotype = SCTP_RECVV_RN;
> + *infolen = len + sizeof(struct sctp_nxtinfo);
> + } else {
> + break;
> + }
> + } else if (cmsg->cmsg_type == SCTP_NXTINFO) {
> + len = sizeof(struct sctp_nxtinfo);
> + if (*infotype == SCTP_RECVV_NOINFO) {
> + if (_infolen < len)
> + break;
> + memcpy(info, CMSG_DATA(cmsg), len);
> + *infotype = SCTP_RECVV_NXTINFO;
> + *infolen = len;
> + } else if (*infotype == SCTP_RECVV_RCVINFO) {
> + if (_infolen < len +
> + sizeof(struct sctp_rcvinfo))
> + break;
> + memcpy(info + sizeof(struct sctp_rcvinfo),
> + CMSG_DATA(cmsg), len);
> + *infotype = SCTP_RECVV_RN;
> + *infolen = len + sizeof(struct sctp_rcvinfo);
> + } else {
> + break;
> + }
> + }
> + }
> +
> + return error;
> +}
> diff --git a/src/lib/sendmsg.c b/src/lib/sendmsg.c
> index 9046174..cb75378 100644
> --- a/src/lib/sendmsg.c
> +++ b/src/lib/sendmsg.c
> @@ -19,7 +19,10 @@
> * Ardelle Fan <ardelle.fan@xxxxxxxxx>
> */
>
> +#include <errno.h>
> #include <string.h>
> +#include <stdlib.h>
> +#include <netinet/in.h>
> #include <sys/socket.h> /* struct sockaddr_storage, setsockopt() */
> #include <netinet/sctp.h>
>
> @@ -104,3 +107,161 @@ sctp_send(int s, const void *msg, size_t len,
>
> return sendmsg(s, &outmsg, flags);
> }
> +
> +static struct cmsghdr *sctp_sendv_store_cmsg(struct cmsghdr *cmsg, int *cmsglen,
> + int type, int len, void *data)
> +{
> + cmsg->cmsg_level = IPPROTO_SCTP;
> + cmsg->cmsg_type = type;
> + cmsg->cmsg_len = CMSG_LEN(len);
> + memcpy(CMSG_DATA(cmsg), data, len);
> +
> + *cmsglen -= CMSG_SPACE(len);
> + if (!*cmsglen)
> + return NULL;
> +
> + return (struct cmsghdr *)((char *)cmsg + CMSG_SPACE(len));
> +}
> +
> +int sctp_sendv(int s, const struct iovec *iov, int iovcnt,
> + struct sockaddr *addrs, int addrcnt, void *info,
> + socklen_t infolen, unsigned int infotype, int flags)
> +{
> + struct sockaddr *addr;
> + struct msghdr outmsg;
> + struct cmsghdr *cmsg;
> + int type, len, i;
> + int cmsglen = 0;
> + char *addrbuf;
> +
> + /* set msg_iov, msg_iovlen, msg_flags */
> + memset(&outmsg, 0x00, sizeof(outmsg));
> + outmsg.msg_iov = (struct iovec *)iov;
> + outmsg.msg_iovlen = iovcnt;
> + outmsg.msg_flags = flags;
> +
> + /* set msg_name and msg_namelen */
> + if (addrs && addrcnt) {
> + outmsg.msg_name = addrs;
> + if (addrs->sa_family == AF_INET)
> + outmsg.msg_namelen = sizeof(struct sockaddr_in);
> + else if (addrs->sa_family == AF_INET6)
> + outmsg.msg_namelen = sizeof(struct sockaddr_in6);
> + else
> + return -EINVAL;
> + addrcnt -= 1;
> + addrbuf = (char *)addrs;
> + addrs = (struct sockaddr *)(addrbuf + outmsg.msg_namelen);
> + }
> +
> + /* get the cmsg length it will need for addr info */
> + for (i = 0, addrbuf = (char *)addrs; i < addrcnt; i++) {
> + addr = (struct sockaddr *)addrbuf;
> + if (addr->sa_family == AF_INET) {
> + len = sizeof(struct in_addr);
> + cmsglen += CMSG_SPACE(len);
> + addrbuf += sizeof(struct sockaddr_in);
> + } else if (addr->sa_family == AF_INET6) {
> + len = sizeof(struct in6_addr);
> + cmsglen += CMSG_SPACE(len);
> + addrbuf += sizeof(struct sockaddr_in6);
> + } else {
> + return -EINVAL;
> + }
> + }
> + /* get the cmsg length it will need for snd/pr/auth info */
> + if (infotype == SCTP_SENDV_SPA) {
> + struct sctp_sendv_spa *spa = info;
> +
> + if (spa->sendv_flags & SCTP_SEND_SNDINFO_VALID)
> + cmsglen += CMSG_SPACE(sizeof(struct sctp_sndinfo));
> + if (spa->sendv_flags & SCTP_SEND_PRINFO_VALID)
> + cmsglen += CMSG_SPACE(sizeof(struct sctp_prinfo));
> + if (spa->sendv_flags & SCTP_SEND_AUTHINFO_VALID)
> + cmsglen += CMSG_SPACE(sizeof(struct sctp_authinfo));
> + } else if (infotype == SCTP_SENDV_SNDINFO) {
> + cmsglen += CMSG_SPACE(sizeof(struct sctp_sndinfo));
> + } else if (infotype == SCTP_SENDV_PRINFO) {
> + cmsglen += CMSG_SPACE(sizeof(struct sctp_prinfo));
> + } else if (infotype == SCTP_SENDV_AUTHINFO) {
> + cmsglen += CMSG_SPACE(sizeof(struct sctp_authinfo));
> + }
> +
We're talkinag about less than 128 bytes of storage here. Instead of checking
all the infotypes and allocating the appropriate cmsglen, why not just declare a
cmsg buffer on the stack that is of the maximum possible size. It would
eliminate a good deal of code here.
Neil
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